Belt drive



March 30, 1937. J. J. O'BRIEN 2,075,297

BELT DRIVE Filed April 3, 1936 F/G. Z

gq INYENTOR. JOHN J 0 5mm BY 457% W ATTORNEY5.

Patented Mar. 30, 1937 UNITED STATES PATENT OFFICE.

. BELT DRIVE John J. OBrien, South Bend, Ind., assignor to South Bend Lathe Works, South'Bend, Ind., a corporation of Indiana Application April 3, 1936, Serial No. 72,461

8 Claims. (Cl. 74-24215) This invention relates to a belt drive, and parthereof and journals a shaft 2I adjacent the forticularly to a belt'drive for bench mounted maward end thereof. The shaft 2I mounts a step chines. pulley 22 in conventional reverse relation tothe The primary object of the invention is to prostep pulley in headstock l6, and the lower porvide belt driving means of this character position of belt IIruns' around said step pulley. 5 tioned beneath and within the overall outline of Shaft 2I also mounts a drive pulley 23 around the bench mounting the machine, whereby which runs a belt 24 driven by a motor mounteddanger of contact therewith by an operator is pulley 25. eliminated. A bracket is mounted on the under side of the A further object is to provide a belt drive of bench top I0 adjacent the rear side of cleat I2 10 this character which is readily controllable and and above cradle I9. This bracket comprises 'a adjustable. I horizontal seeming flange 26, and vertical flange A further object is to provide a belt drive of 27 in spaced parallel relation to the inner face of this character with a control member positioned cleat I2, an inclined flange 28 perpendicular to exteriorly of the outline of the bench. flange 21 and a horizontal tubular member or 15 A further object is to provide a belt drive of bearing 29 at the lower end-o-f'flanges 21 and 28. this character with novel means for selectively The bracket is of integral construction, and the locking the same in operative and inoperative bearing portion 29 thereof projects forwardly of relations. flange 2'I'to project through an opening 30 in A further object is to provide a belt drive of the cleat I2. The flange 28is provided with a this character with novel belt tightening means. thickened portion 3I adjacent bearing portion Other objects will be apparent from the de- 29'Eand the bracket includes a lug 32 depending scription and the appended claims. from the lower side of the bearing at the inner In the drawing: end thereof, all as best illustrated in Fig. 5, and

Figure l is a side view illustrating the drive for purposes to be hereinafter set forth. 25 means mounted on a bench to drive a bench A crank 33is positioned rearwardly of the lathe, some of the parts being" illustrated in secbracket, and includes'a forwardly extending shaft tion and other parts being broken away. 34 journaled in bearing 29 and projecting for- Figure 2 is a fragmentary view in front elevawardly therefrom; At. its forward end the tion. shaft 34 mounts a crank arm 35 carrying a Figure 3 is an enlarged view of the control handle 36, said crank arm and handle being means with parts shown in section. spaced forwardly from cleat I2. Apin 3'! is jour- Figure 4 is a fragmentary view of the control naled' in' the free end of crank 33 in parallel means in rear elevation. relation to shaft 34,-and mounts a head 38 at Figure 5 is aview of abracketinrear elevation. its rear end. The forward end of the pin 31 35 Referring to the drawing, which illustrates the projects from crank 33 and is adapted to abut preferred embodiment of the invention, the nuboth the bracket shoulder 3| and the bracket lug meral III designates the top of a bench which is 32, as best illustrated in Fig. 3. provided with legs and a front longitudinal The cradle I9 carries a forwardly projecting .1 cleat I2. The bench top is provided with a pair arm 40 in substantially vertical alignment with 40 of passages I3 therethrough. A small lathe I4 or shaft 34, and said arm terminates in a bearing other belt driven machine adapted to be mounted portion 4| Whose axis is substantially. perpenon the bench, is provided with a hollow support dicular to theaXis about which the cradle is piv- I5 at the end thereof supporting the headstock oted to support I8. In bearing 4| is journaled a .55 I6 or other driving head and communicating with pin 42 whose forward end mounts a head 43. A 5 the passages I3, whereby the runs of a drive belt pair of rods 44 interconnected by a turnbuckle 45 Il passing over the conventional headstock pulley are each provided with perpendicularly bent ends may extend downwardly through the support I5 46, and said bent ends are journaled in suitable and passages I3. apertures in the heads 38 and 43 perpendicularly One or more supports I8 depend from bench to the pivot pins 31 and 42, respectivel of said 50 top III at the rear thereof, and at the lower end heads. thereof is pivotally mounted one end of a nor- In the operation of the device, the crank 35, mally substantially horizontal cradle I9 which 36 provides means for rotating crank 33 to raise extends forwardly therefrom. The cradle I9 and lower head 38, and thereby pivot the cradle mounts a drive motor 20 adjacent the rear end I9 upwardly and downwardly. In this move- 55 ment, it will be seen that the perpendicular relation of the pivot mounting of the respective heads 38, 43 to the pivot connections 46 of the rods 44 with said blocks, accommodates the variations in angular position which the parts must assume incident to the arcuate swinging of crank 33 and the arcuate raising andlowering movement of the cradle carried head 43. It will also be noted that the shoulder 3| and lug 32 of the bracket, see Figs. 4 and 5, have their inner faces in substantially vertical alignment slightly laterally ofi-set from the pivot axis of bearing 29. This permits the crank 33 to rotate slightly more than 180 degrees between the shoulder and lug, which rotation is stopped by engagement of the pin 31 with said shoulder and lug, and also positions said pin 31 slightly overcenter with relation to shaft 34 at each extreme of movement thereof, as best illustrated in Fig. 4. Therefore, when the parts are shifted to the position illustrated in Figs. 3 and 4,; the slight overcenter relation of pin 31 to shaft 34 serves. to effectively hold the cradle IS in raised position; and when the parts are reversely positioned with pin 31 engaging lug 32 as illustrated in Figs. 1 and 2, the overcenter relation locks the cradle in depressed position'against the tension of the belt I! efiected thereby. It will also be seen that the interposition of the turnbuckle 45 in the means connecting the cradle and the operatingmechanism permits a wide range of adjustment of the belt tension applied by the device. It will also be seen that the drive parts, except crank 35, 36 are positioned within the overalloutline of the bench.

I claim:

1. The combination with a bench, and a belt driven machine mounted thereon, of a pulley mounting'pivoted beneathsaid bench, a terminal member journaled in the free end of said pulley mounting, a bracket carried by said bench, a crank journaled in said bracket, a terminal member journaled in the free end of said crank,

. unit, a crank journaled in said bracket, meansv means for interconnecting said terminals, said interconnecting means being pivoted to said terminals, and opposed stops on said bracket engageable by said last named terminal member for stopping the same in slightly overcenter position at each extreme of its movement.

2. The combination with a bench, a belt driven machine mounted on said bench, and a drive belt, of abelt driving unit pivoted beneath said bench, a bracket carried by said bench above said driving interconnecting said crank and drive unit, and

- opposed stops on said bracket engageable by said means for stopping the same in slightly overcenter position, one stop when engaged by said means cooperating with the means to hold said drive unit in belt tensioning position and the other stop when engaged by said means cooperating with the means to hold said drive unit raised in belt releasing position.

3. The combination with a bench, a belt driven machine mounted on said bench, and a drive belt,

of a belt driving unit pivoted beneath said bench, a bracket carried by said bench above said driving unit and including a, pair of opposed stops, and

crank operated means associated with said bracket and connected to said driving unit for adjusting the vertical position of said driving unit for selectively applying and releasing belt tension and engaging" saidstops whereby to be held at vertically spaced'opposite substantially dead center extremes of movement, the beltten sion applying and releasing positions.

' 4. The combination with a belt driven machine, of means for selectively applying or releasing belt tension comprising a shiftable driving unit, a part pivotally mounted on said unit, operating means, a part pivotally mounted on said operating means, and a link connecting said parts and pivoted thereto perpendicularly to the pivot axes thereof.

5. The combination with a belt driven machine, of means for selectively applying or releasing belt tension comprising a shiftable pulley sup-,

port, a part carried by and rotatable relative to said support, a bracket having a pair of opposed stops, a crank carried by' said stationary bracket and engageable with said stops, a part carried by and rotatable relative to said crank and means connecting said rotatableparts and pivoted thereto perpendicularly to the axes thereof.

6. The combination with a belt driven machine, of means for'selectively applying and releasing belt tension comprising a shiftable support for a driving member, a head rotatably carried by said support, operating means including a rotatable head, means connecting said heads and pivoted thereto perpendicularly to the pivot axes thereof, and stops for holding said operating means at. substantially dead center position in tension applying and releasing relation.

'7. The combination with a, belt driven machine, of means for controlling belt tension comprising a pivoted support for a belt driving member, a head pivoted to said support about an axis perpendicular to the pivot axis of said support, a crank, a bracket journaling said crank and including a pair of opposed stops engageable by said crank, a head pivoted to said crank parallel to the crank axis, and a member connecting said heads and pivoted thereto about axes perpendicular to the pivot axes thereof.

8. The combination with a belt driven machine, of means for selectively applyingv and releasing belt tension comprising a pivoted support for a belt driving member, shiftable operating means spaced from said driving member, an elongated link extending between said driving member and JOHN J. OBRIEN. 

